Cyber Security Lab
IT Security & IT Forensics Exercises

Web Forensics

Cache Manipulation

Load images using various techniques to avoid being cached.

Exercise

Various images are loaded and displayed on the pages.

What other hidden images can be found?

How does the transfer from the server to the client look like?

Exercise B: Advanced Example

On this page you can see three cats. Where are the correct files?

cat4
cat5
cat6
Solution of the exercise

The first image is encoded in Base64 and integrated directly into the HTMl file. So there is no extra call to the server.

In the second picture, an exclusively transparent PNG file is loaded. The actually visible image is defined as a background image using CSS. The image is also Bas64 encoded, but embedded in the CSS file.

The third figure uses the HTML picture element. Various photos are loaded here depending on the resolution of the client's screen.



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